In telecommunications networks, the quality of service provided by a radio bearer (radio channel) depends on block error rate(BLER), delay, and data rate.). BLER is the measure of the ratio of the number of erroneous blocks received divided by the total number of blocks transmitted to the receiver.
In radio transmission schemes used in known mobile telecommunications networks, there are two strategies for providing a service with a low block error rate. One approach, as used in the network shown in FIG. 1, is simply to increase the power of transmitted signals (transmit power) sufficiently to increase the data reception accuracy (reliability of the radio link) up to an acceptable level. Unfortunately, the use of high transmit powers leads to an increase of the interference level which in turn leads to capacity losses. The other approach is to use a mechanism for the retransmission of the blocks that are received with an error, as shown in FIG. 2. The use of a retransmission technique leads to fluctuations in data rate. Whenever the retransmission rate increases, the end to end data rate decreases, (and vice versa). That is not acceptable for ‘Streaming’ services, such as video, as these require block error rate and data rate (i.e. throughput) at constant levels, although even fairly long delays in transmitting data are acceptable.